Old tires, plastic bags and lots of other trash are found in the Susquehanna River every year, and every year, volunteers get together to help keep it clean as part of Earth Day efforts.

Billy Boniface and his daughter, Bethany, volunteered their time Monday to help keep the Susquehanna River clean. The Darlington family said they spend lots of time on the water and don't want to see piles of trash floating everywhere.

The Bonifaces joined other volunteers for a river sweep at Concord Point Park in Havre de Grace, a roadside and shoreline cleanup ahead of Earth Day.

"We all have to do our part to keep the river clean, and we all work hard to do so," Billy Boniface said.

This is the 14th year for the event, which is sponsored by the Lower Susquehanna Heritage Greenway.

"We find everything from propane tanks to mufflers to lots of plastic -- even kitty litter pails and planters and things like that that don't really belong in the water," said LSHG executive director Mary Ann Lisanti.

The river sweep will include seven locations throughout Harford and Cecil counties. In the past, more than 72 tons of trash and debris were removed, officials said.

"Plastic bags are one of the worst because, unfortunately, fish swallow them, and sometimes birds mistake them for food," Lisanti said.

Some of the volunteers had some words of advice for litterers.

"Think twice before you do it. They don't realize what the consequence is, and it builds up over the years," Bethany Boniface said.

Volunteers like the Bonifaces said they hope all their hard work pays off for years to come to help keep the Susquehanna River clean.

Organizers said about 700 people signed up so far for Saturday's River Sweep at Tydings Park in Havre de Grace. It runs from 9 a.m. until noon, and there's still space to register. For more information, click here.